text: Phenyl azide ("diazoamidobenzol"), was prepared in 1864 by Peter Griess by the reaction of ammonia and phenyldiazonium. In the 1890s, Theodor Curtius, who had discovered hydrazoic acid (), described the rearrangement of acyl azides to isocyanates subsequently named the Curtius rearrangement. Rolf Huisgen described the eponymous 1,3-dipolar cycloaddition.
  The interest in azides among organic chemists has been relatively modest due to the reported instability of these compounds. The situation has changed dramatically with the discovery by Sharpless et al. of Cu-catalysed (3+2)-cycloadditions between organic azides and terminal alkynes. The azido- and the alkyne groups are "bioorthogonal", which means they do not interact with living systems, and at the same time they undergo an impressively fast and selective coupling. This type of formal 1,3-dipolar cycloaddition became the most famous example of so-called "click chemistry" (perhaps, the only one known to a non-specialist), and the field of organic azides exploded.